ML17286A542

Proposed Tech Specs Re Scram Discharge Vol Trip Setpoints

ML17286A542
Person / Time
Site:	Columbia
Issue date:	12/31/1990
From:	WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
Shared Package
ML17286A541	List: ML17286A540 ML17286A542
References
NUDOCS 9101100003
Download: ML17286A542 (8)

Text

TABLE~ ~3.6-2 o 0'v CONTROL ROD BLOCK INSTRUMENTATION SETPOINTS ZO w Cl TRIP FUNCTION TRIP SETPOIHT ALLOMABLE VhLUE DO ~~

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1. ROD BLOCK HONITOR OO AO > < 0.66 M + 4(C < 0.66 M + 43K FQ o b. Inoperative, H.A. S.A.

Bol c. Downscale > 5X of BATED THERMAL PINER > 3X of RATED THERNL POWER Qs Qh) 2. APRH Vow 6-

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a. Flow Biased Neutron Flux Upscale < 0.66 M + 42K* c 0.66 M+ 455" w b.: Inoperative H.A. Q.A.

c. Downscale > 5X of RATFD THERHhL POWER > 3X of RATED THEfNhL POMER t4 d. Neutron Flux " Upscale, Startup < 12'f RATED THERHAL PS/ER c 1SX of RRTED THERHAL POWER

3. SOURCE RANGE HONITORS 0

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a. Detector not full in N.A. N.h.

b. Upscale < 1 x 10 cps < 1.6 x 10 cps

c. Inoperative H.A. H.A.

I d. Dowrnscale > 0.7 cps > 0.5 cps 63l

4. INTERHEDIhTE RANGE HONITORS

a. Detector not full in N.h. N.A.

a

b. Upscale'.

< 108/125 divisions of full scale < 110/125 divisions of full e Inoperative B.A. R.A.

d. Downscale > 5/125 divisions of full scale > 3/125 dlvlslons of full sod

5. SCRAN DISCHhRGE VOLUHE 5 fvl C3 6.

a.

b.

Mater Leve1-High Scr'm Trip Bypass REACTOR COOlANT

a. Upscal e SYSTBl RECIRCULATION FLOM 527 H.A.

f in. elevation 108/125 divisions

< 527 Q.A.

ft in. elevation

< 111/125 divisions t

of fu11 scale of full scale

b. Inoperative N.A. N.h.

CD c. Coeparator < 1(C flow deviation < 11K floe deviation e verage ower ange Honitor rod block funct ion is varied as a function of recirculation loop flow (M). The trip setting of this function aust be maintained in accordance with Specification 3.2.2.

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4'ABLE 2.2.1-1 (Contim(ed),

REACTOR PROTECTION SYSTEH INSTR(lHENTATION SETPOIHTS ALLOWABLE'LLOWA&LE fUNCTIONAL UNIT TRIP SETPOINT VALUES J

7; Primary Containment Pressure - High < 1.6& psig

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&. Scram Oischarge

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Volume Water Level - jligh . q4(

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Level Transm) tter < 529 6" e evation < 529'" elevation

b. float Switch y < 529'Q6" elevation < 529'" elevation

9. Turbine Stop Valve - Closure < 5X closed < 7X closed

10. Turbine Control Valve Fast Closure, .

'rip Oil.Pressure - Low > 1250 psig > 1000 psig I'p ll.

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y Reactor Node Switch Shutdown Pos i tion

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H.A..

Hanual Scram H.A.

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CSNTROLL'ED COPY LIMITING SAFETY SYSTEM SETTING BASES REACTOR PROTECTION SYSTEM INSTRUMENTATION SETPOINTS (Continued)

8. Scram Oischar e Volume Water. Level-Hi h The scram .discharge volume receives the water displaced by the motion of the control rod drive pistons during a reactor scram. Should this volume fill up to a point where there is insufficient volume to accept the displaced water at pressures below 65 psig, control rod insertion would be hindered. The reactor is therefore tripped when the water level has reached a point high enough to indicate that it is indeed filling up, but the volume is still great enough to accommodate the water from the movement of the rods at pressures below 65 psig when they are tripped. The scram discharge volume high level alarm setpoint I'z ..t3

"'"( " nd-SPPB ss equi. valent to 32 gallons for SOV" Mvat4o The scram setpoint is

+Runs-for-SGV-"A " and-SOV-"B " (S29 6" eleva

9. Turbine Sto Valve"Closure The turbine stop valve closure trip anticipates the pressure, neutron flux, and heat flux increases that would result from closure of the stop valves. With a trip setting of 5X of valve closure from full open, the resultant increase in heat flux is such that adequate thermal margins are maintained during the worst case transient assuming the turbine bypass valves fail to operate and an RPT occurs.

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10. Turbine Control Valve Fast Closure Tri Oil Pressure-Low The turbine contro] valve fast closure trip anticipates the pressure, neutron flux, and heat flux increase that could result from fast closure of the turbine control valves due to load rejection with or without coincident failure of the turbine bypass valves. The Reactor Protection System initiates a trip when fast closure of the control valves is initiated by the fast acting solenoid valves and in less than 30 milliseconds after the start of control valve fast closure. This is achieved by the action of the fast acting solenoid valves in rapidly reducing hydraulic trip oil pressure at the main turbine control valve actuato~ disc dump valves. This loss of pressure is sensed by pressure switches whose contacts form the one-out-of-two-twice logic input to the Reactor Protection System. This trip setting, a faster closure time, and a different valve characteristic from that of the turbine stop valve, combine to produce transients which are very similar to that for the stop valve.

Relevant transient analyses are discussed in Section 15.2.2 of the Final Safety Analysis Report.

ll. Reactor Mode Switch Shutdown Position The reactor mode switch .Shutdown position is a redundant channel to the automatic protective instrumentation channels and provides additional manual reactor trip capability.

WASHINGTON NUCLEAR - UNIT 2 B 2-9

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PROPOSED TEC CAL SPECIfICATION INSERT CHANG 0 BASES I

C 4 SECTION 2.0 PARAGRAPH 8 for scram discharge volume 'A'525' 1/2" elevation) provides 87. 1 gallons of margin above the required 617.9 gallons of free volume required for a reactor scram. The scram discharge volume high level alarm setpoint for scram discharge volume 'B'524'" elevation) provides 91.3 gallons of margin above the required 617.9 gallons of free volume required for a reactor scram. The rod block setpoint for scram discharge volume 'A'nd 'B'527'" elevation) provides 77.2 gallons of margin above the required 617.9 gallons of free volume required for a reactor scram. The scram setpoint for scram discharge volume 'A'nd elevation) provides 64.9 gallons of margin above the required 617.9

'B'529'"

gallons of free volume for a reactor scram.

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